K&N air filter? If it were my engine I'd be a little worried, you can try the very technical test of running your fingernail across the scoring. If you can feel it then worry more. And if you're running a K&N throw it in the trash where it belongs.

Although on second thought, the scoring looks a little large to just be caused by dirty air entering the engine. Lots of time dirty air will just uniformly wear the cylinder walls. This scoring may be something else...to my eye it looks troubling. But there are a lot of other guy's here that I'm sure have more experience with things like this than I do. My expertise is general heavy line and engine performance issues with late model automobiles....although I've done about everything one time or another.

 

. Looks rather typical... but I'd try to clean off the top piston ring before putting the heads back on... use a shop vacuum... turn the engine over and wipe out any crud the pistons leave behind... put a fresh smear of oil on the cylinder bores... is the crankcase oil clean? Might cut open the oil filter and see what's in there...

 

I changed the oil about a month ago. Since I have the heads off I will be needing to change it again so I can pull it and the filter and make sure there are no surprises.

I currently have a 14x3 fram air filter. Needs replacing as it is very dirty. Will be picking up a new one when I put the heads back on.

Now and of the vertical scratches you see are barely deep enough to feel/catch your finger nail. I was curious about the spots that look hazy. I can feel a

 

I read the other thread, I was under the impression this was a newly built engine? If so I would call that atypical scoring. I wouldn't worry about the staining of the walls unless it's eaten into the cylinder. Are you using any type of additive in the oil? Moly, or another friction modifier?

 

Looks more lke a coolant leak into the cylinder to me. You can see a couple marks going circumferentially in the cylinder in 2 spots. Like coolant laid there and stripped the oil film off, causing corrosion/wear.
Also the long gouge could be caused by the same.
Has I been overheated? Does it use coolant?

 

Never overheated. Heads were pulled due to leaking head gaskets so that would explain the corrosion.

 

Probably of no consequence as the hone cross hatch marks are still pretty much visible. If you have access to a 'floppy' glaze breaker hone, maybe a couple trips up and down with it would smooth things out.

Dave W